[Sync EN] install/unix: Fixed typo (#5761)

Commit: `https://github.com/php/doc-en/commit/e07f764c8e4234d1195536ffed2eaf19c849ce50`
PR: `https://github.com/php/doc-en/pull/5761`

**Archivos ES a actualizar**
- `install/unix/source.xml`

